You know Steve, I've said it a thousand times before, but the higher initial purchase cost is irrelevant to your costings as you will get that back when you sell the vehicle on. In many cases diesels depreciate less than thier petrol equivalents so you'll be even better off ;)

My calculations tell me that sometime after 3 years of ownership, the diesel engine premium will be paid off. This is my first diesel, and after just 14 months of ownership, I never want to go back to gasoline (petrol).

I know what you mean - back in the '90s, before i ever worked out MPGs, i used to stick just a fiver in at the pumps.
It seemed that the big diesel nissan bluebird would go almost twice as far as the petrol version of the same car, and further than the small petrol vauxhall nova on £5 of fuel.
Apart from a couple of mistakes or emergency purchases, every one of my couple dozen rides since has been diesel.
Until i got this Prius!
Now the same passion i had for diesel i hold for hybrids - the fuel economy of the Prius is slightly better than a diesel supermini and around 50% better than a diesel of a comparative size.
The hybrid premium may be higher, may take longer to recover.
Free road tax helps. The nature of the hybrid system makes driving it more of a fun eco game than with the diesel - chasing the various states of charging and EV use.
When the Honda CR-V is to be replaced (with the wifes choice), i am trying to lead her towards the Mitsubishi Outlander PHEV...!
On the other hand, she likes the look of the Dodge Nitro (as do i), shame shes a bit snobbish about the age of them.
I'd most likely only buy hybrids now, but i'd still be happy with a diesel in our "fleet".